occur用法

occur的意思是“呈现在视野、思想、意识中”，常与介词to连用，意为“发生”“想起”等。occur一般只用作不及物动词，含有出乎意料的意味。

例句
1.If headaches only occur at night,lack of fresh air and oxygen is often the cause.
如果只是在晚上头疼，那常常是由于缺乏新鲜空气和氧气的缘故。
2.The cattle disease occurs more or less anywhere in Africa where the fly occurs.
在非洲凡是有这种蝇虫的地方，几乎都会出现这一牛病。
3.It did not occur to me to check my insurance policy.
我没有想到要核实我的保险单条款。
4.The crash occurred when the crew shut down the wrong engine.
机务人员关错了引擎，随即飞机坠毁。
5.In March 1770,there occurred what became known as the Boston Massacre.
1770年3月在那里发生了后来闻名的波士顿惨案。